Availability and Prediction Performance Evaluation of BDS-3 Satellite Clock Error Products

With the completion of BDS-3 constellation deployment in China, various analysis centers have begun to provide BDS-3 precise satellite clock products. Satellite clock error is a key product of GNSS Navigation Positioning and Timing (PNT) technology. Therefore, evaluating the availability and prediction performance of BDS-3 satellite clock error products is of great significance to the application of BDS-3 PNT technology. This paper describes the current BDS-3 constellation status, evaluates the availability of the clock error products of three analysis centers, gives the detailed implementation method and specific steps of the prediction model, uses the model to predict BDS-3 clock error, and finally evaluates the performance of BDS-3 satellite clock error products. One-month BDS-3 precise clock products provided by GFZ, CHD, and WHU analysis centers are used for product availability analysis and prediction experiments. The results show that: (1) The availability of the C38-C46 satellites clock error is much worse than other BDS-3 satellites according to the difference between analysis center products. The clock STD precision is about 0.19 ns for C19-C37 satellites while it is about 0.53 ns for C38-C46 satellites. The clock phase jump occurs in the day boundary; (2) The precise clock error provided by WHU analysis center is used to predict the BDS-3 satellite clock error. The prediction accuracy of BDS-3 within 30 min is between 0.025 ns and 0.074 ns. When the prediction arc increases to 1 h, the accuracy is between 0.056 ns and 0.103 ns. The prediction accuracy of some rubidium clocks is 0.015 ns worse than that of hydrogen clocks. The precision statistics of BDS-3 and BDS-2 satellite clock prediction during the same time show that the prediction accuracy of BDS-3 clock error is 0.059 ns, which is significantly better than the accuracy of 0.295 ns for BDS-2 satellite.